I can see you are using windows, but have you installed LMMS1.1.3?
If so i recommend you to follow these guidelines:
*Back-up your own stuff, if you have any
*Un-install current installation
*(re)move the config dot-file
https://lmms.io/wiki/index.php?title=LM ... h_Settings
*download a fresh new installation-pack either x32 or x64 of
LMMS 1.2.0 RC7 Orange buttons!
https://lmms.io/download/#windows
*re-install as administrator and grant all users access
Let us know the outcome :)
Besides that, since you are new in Forum
Welcome seb16120 !
Here are all important links:
http://lmms.io/forum/viewtopic.php?f=1&t=4740
-A few rules and useful forum instructions